A veneer is a slice of wood that’s typically only about 1/16th inch thick or less. Below the veneer are plies of wood glued together to form a base to support the skin. Veneered plywood is strong, durable and very stable. It also costs much less to produce than solid wood panels, because the plies are made of less desirable material from cheaper woods.
Sanding veneers means using only fine-grit sandpaper, no matter the method used for sanding. A 220-grit paper helps ensure that sanding will not go too deep into the wood, beyond the veneer and into the plies. Grits as low as 120 may be used. The amount of time spent sanding the surface of the veneer should be minimized to avoid cutting in too far.
A palm sander removes only a small amount of wood fiber at a time and is easy to control. But power equipment still removes more wood more quickly than hand sanding. To avoid gouging the veneer, try scribing a wavy, light pencil mark across the area that needs sanding. Stop sanding with a palm sander as soon as the pencil mark begins to disappear. Switch over to hand sanding to finish the table top. Keep the palm sander flat to the table’s surface. Tipping the tool, even slightly, can cause the sandpaper to eat into the veneer.
Wrap 220-grit sandpaper around a block of wood to ease the stress on your fingers and to keep the sandpaper flat against the table top. Always sand in the direction of the grain to avoid leaving telltale scratches across the surface that could invite the need for further sanding. Move the block back and forth only enough to lay down wood fibers and create a smooth surface that’s ready to accept stain and finish.